The present invention is concerned with a process for preparing a dispersion comprising a continuous fat phase and a dispersed gelled aqueous phase. Prior art methods of preparing such low fat continuous spread products first cooled a gelatin containing water continuous composition to a temperature below the gel setting temperature to allow the formation of a gel structure. The resulting water continuous composition was then sheared in a crystallizing inverter unit (C* unit) to invert the water continuous composition into small gelled aqueous beads and form a fat continuous dispersion. It was recognized in the art that this process aided in the control of the aqueous phase droplet size distribution in the final dispersion and that reduced droplet size and distribution are advantageous in determining appearance, flavor and salt release and rheology of the dispersion. Additionally, smaller droplet size and distribution in the final product improves microbial stability. See U.S. Pat. No. 5,151,290 issued to Norton et al. on Sep. 29, 1992.
However, it was observed that low fat containing products which are also high in trans fatty acid content produced by the known methods still exhibited microbial instability. The average droplet of such products still average greater than about 20 microns and provide a possibility for microbial contamination.
The prior art focuses on improving the production process by utilizing cooling temperatures just below the gel setting temperature of the level of gelatin contained in the aqueous phases of these products.
Whereas shelf stable products can thus be produced, the process needs to be improved to produce low trans fatty acid containing spreads. It has been surprisingly observed that certain temperatures at which low trans containing fats crystallize in the process synergistically both crystallize the fat and gelling the gelatin so as to form products with much smaller aqueous droplets than those that could be produced in the prior art.
There therefore exists a need for an improved process for making a fat continuous product having less than 40% fat which has both good organoleptic properties and which is microbiologically stable.
Another object of the invention is to provide an in line production process which is flexible enough to be modified as the trans fatty acid levels of the spread products are reduced.